Summary of influenza A subtypes in wild birds from GenBank and 49 studies

Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify all competent hosts and subtypes. We examined 11,870 GenBank records to provide insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 49 study locations and over 250,000 birds. We built regional and global virus subtype incidence-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype diversity. Our study identifies surveillance steps needed to develop a more balanced approach that can explore the influence of host and virus subtype biodiversity on emergence and transmission, and a targeted sampling scheme to detect 75% percent of global and regional circulating virus subtypes.